Design And Performance Analysis Of Key Components Of High-speed Motor Deep Groove Ball Bearings For NewEnergy Vehicles

Compared with the traditional vehicle,the driving motor speed of new energy vehicles is higher,which can reach 16000 r/min,and the performance requirements of motor bearings are more stringent.Therefore,it is necessary to improve the design and research of the bearing inner and outer rings,cages and rolling elements under the working conditions that can meet the use of the new energy vehicle.In this paper,the 6208 deep groove ball bearing used in high-speed motor of new energy vehicle is taken as the research object.The main research contents are as follows:(1)Based on the high-speed and high-temperature characteristics of new energy vehicle bearings,the use conditions of different plastic cages were studied,and the materials of inner and outer rings and cages were determined.In view of the influence of centrifugal force on the cage at 16000 r/min,the cage pocket radius,lock size and beam thickness were optimized by orthogonal design.(2)The static analysis of the deep groove ball bearing is carried out by using ANSYS Workbench software.The results show that the error between the simulation value and the theoretical value of the contact stress between the rolling body and the inner and outer rings is less than 10%,which verifies the reliability of the simulation software.At the same time,the ANSYS Workbench simulation software was used to analyze the stress and deformation of the cage before and after the improvement,and the displacement change of the cage lock before and after the improvement is emphatically studied.The results show that the improved cage can withstand a higher speed than before.At 16000 r/min,the distance of cage lock out still has a certain safety range,and its maximum allowable rotating speed can reach 18000 r/min.The results showed that,in terms of the bending vibration frequency of the cage surface,the ratio of the improved cage to avoid resonance was increased by 22%～51%compared with that before the improvement.In terms of the overall tilt deformation of the cage and the vibration frequency of the umbrella deformation,the proportions that can effectively avoid resonance increase by 46%and 40%,respectively.(3)Based on the ANSYS Workbench and ANSYS/LS-DYNA joint simulation,the dynamic simulation of the bearing is performed to obtain the dynamic characteristics of the inner and outer rings,rolling elements and cages during the high-speed running contact process,and the displacement,velocity and the changes in acceleration characteristics are compared with the radial and axial displacement of the cage centroid before and after the improvement.The results show that the shake of the cage is relatively smooth after the improvement.(4)Using the high-speed bearing life testing machine,the deep groove ball bearing before and after the improvement was tested under 16000 r/min and 500 N radial load.The test data showed that the vibration and temperature rise of the improved bearing in the operation process were relatively more stable than before.